Boiler-flue scraper.



PATENTE'D MAY 7, 1907.

A. B. MUIRHEAD.

BOILER PLUE SGRAPER.

APPLIOATIYON I'ILED'APR. 18. 1906.

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ANDREW ERSKINE MUIRHEAD, OF GLASGOW, SCOTLAND.

BOllLER-FLUE SGPAPER.

Specification of Letters Patent.

Eatented May 7, 1907.

Application filed April 18, 1905. Serial No. 256,242.

1'0 a, w/z/mn it may concern.-

Be it known that I, ANDREW ERSKINE MUIRI-IEAD, Cart Forge, Cathcart, Glasgow, Scotland, have invented certain new and useful Improvements in or Relating to Boiler- Flue Scrapers, of which the following is a specification.

My invention has for its aim the keeping the tubes of marine, locomotive, and multitubular boilers and also tubes of the air heating chambers of force draft free from soot, etc. IVith this end in view I place in each tube a round or square rod bent into helical form or a sheet bent spirally like present retarders or other suitable form. Those I rotate when the soot is disturbed and the air current assisted by their form drives the soot toward smoke box. A plate inside smoke box engages those rods by pins, slots or otherwise. This plate is put in motion by a shaft passing through the smoke box, which is in turn put in motion by hand or power, constant or intermittent.

' In order that my invention may be properly understood and readily carried into effect, I have hereunto appended one sheet of drawings, of which Figure 1 is a part longitudinal section and part elevation of a multitubular boiler necessary to illustrate my invention. Fig. 2 is a front or end view of the boiler tubes. Fig. 3 is a front view of perforated plate or grid with cranks and arms.

A indicates the boiler tubes, the upper most of which the better to illustrate my invention is in section as shown. The helical rod or bar B traverses the tube from end to end and is seen to terminate with a bent up end I) which protrudes from the outside of the said tubes A by which the rod or bar is rotated within the tube. The said rod or bar B may be rotated by any well known mechanicaljfmeans. One way of accomplishing this object is shown on the drawings. A perforated plate or grid 0 is mounted within the smoke box upon an upper and lower pair of crank shafts D and ,D D and D The upper pair of crank shafts D and D are connected together by a connecting rod (Z. The crank shaft D being the driving shaft receives its motion either by hand or power continuously or intermittently. The perforated plate or grid 0 is mounted with a number of short projecting arms E which engage the bent up ends I) of the rods or bars-B. The motion imparted from the crank shafts to the projecting arms is an orbital one and this being communicated to the rods or bars B produces the necessary rotation. Fig. 2 illustrates the position and centers of crank shafts and the dotted lines indicate the throw of the cranks.

I claim.

In a multitubular steam generator, the combination with the boiler tubes and the smoke box, of a spirally bent stirrer rod arranged in each of said tubes and having one of its ends extending outside of the tube and bent laterally to the tube within the smoke box, a motion plate arranged within the smoke box, and having a plurality of arms engaging the lateral ends of the stirrer rods, and a driving shaft having one end connected to the motion plate and having its other end extending outside of the smoke box.

In Witness whereof I have hereunto set my hand in the presence of two witnesses.

ANDREW ERSKINE MUIRHEAI).

WVitnesses:

JOHN LIDDLE, CATHERINE HAMILTON. 

